Ubuntu

Ubuntu bionic (18.04)

protobuf 3.6 is needed for ubuntu 18.04, so add the ppa from Maarten Fonville:

sudo add-apt-repository ppa:maarten-fonville/protobuf

Ubuntu cosmic (18.10)

protobuf 3.6 is included in ubuntu cosmic so we don't need to install a third party PPA.

Install needed prerequisites as packages

sudo apt update
sudo apt-get install cmake git g++ libnotmuch-dev libglibmm-2.4-dev libgtkmm-3.0-dev libwebkit2gtk-4.0-dev libgmime-2.6-dev libsass-dev libpeas-dev libgirepository1.0-dev libboost-all-dev libgmime-3.0-dev libprotobuf-dev libvte-2.91-dev protobuf-compiler ruby-ronn #ronn

Then follow the README.md installation instructions.